1 Technical Field
The present invention relates to a control apparatus for a rotating electric machine, the control apparatus being applied to a system which includes the rotating electric machine and an electric power converter, the rotating electric machine including a stator having a winding wound therein and a rotor having magnetic poles formed therein, the electric power converter being electrically connected with the rotating electric machine to supply a drive current to the winding and thereby drive the rotating electric machine.
2 Description of Related Art
Japanese Patent No. JP3366858B2 discloses a control apparatus for a rotating electric machine. The control apparatus includes a memory and a correction information generating circuit. The memory stores therein information on variation in an electromagnetic force acting on a stator core. The correction information generating circuit generates, based on the electromagnetic force variation information read out from the memory according to a magnetic pole position of a rotor, correction information for correcting the electromagnetic force variation. Here, the electromagnetic force variation information denotes information on variation in a radial component of the electromagnetic force acting on the stator core. The control apparatus corrects, based on the correction information, the waveforms of harmonic currents supplied to stator windings, thereby suppressing the variation in the radial electromagnetic force acting on the stator core.
The inventors of the present application have encountered a problem that apart from variation in a radial electromagnetic force acting on a stator, variation in a radial electromagnetic force acting on a rotor may cause vibration and noise of a rotating electric machine to increase. To solve this problem, it may be considered to supply stator windings with harmonic currents, which are set for reducing the variation in the radial electromagnetic force acting on the rotor, and thereby reduce the variation in the radial electromagnetic force. However, due to differences between individual rotating electric machines that are mass-produced, the magnetic flux characteristics of magnetic poles vary between individual rotating electric machines. Moreover, with the variation in the magnetic flux characteristics, the harmonic currents suitable for reducing the variation in the radial electromagnetic force may also vary between individual rotating electric machines. Therefore, to reduce the variation in the radial electromagnetic force, it is required to determine the suitable harmonic currents for each individual rotating electric machine.